No abstract

Two tetraploid (2n = 4x = 40) peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) germplasm lines, GP‐NC WS 16 (SPT 06‐06) (Reg. No. GP‐235, PI 669445) and GP‐NC WS 17 (SPT 06‐07) (Reg. No. GP‐236, PI 669446), derived from interspecific hybridization, were developed in the peanut genetics program at North Carolina State University (NCSU), Raleigh, NC. These two lines were tested extensively by the North Carolina Agricultural Research Service from 2006 through 2012 in disease evaluation tests. They have unique alleles introgressed from the diploid (2n = 2x = 20) wild species, A. cardenasii Krapov. & W.C. Gregory. The germplasm lines are also unique in that they exhibited multiple disease resistances superior to the germplasm lines derived from A. cardenasii that were released previously by NCSU. Resistance to multiple diseases included early leaf spot (ELS), Cylindrocladium black rot (CBR), Sclerotinia blight (SB), and tomato spotted wilt (TSW). One of the lines, GP‐NC WS 17, also exhibited drought tolerance in field and greenhouse studies. Thus, it can be concluded that these two peanut germplasm lines derived from diploid wild species have multiple biotic stress resistances, specifically for ELS, CBR, SB, and TSWV, as well as abiotic stress resistance in the case of GP‐NC WS 17. These two lines should provide unique, improved germplasm for breeders interested in multiple disease resistance and in expanding the germplasm pool of A. hypogaea.

About 1% of individuals with autism or types of pervasive developmental disorder have a duplication of the 15q11-q13 region. These abnormalities can be detected by routine G-banded chromosome study, showing an extra marker chromosome, or demonstrated by fluorescence in situ hybridization (FISH) analysis, revealing an interstitial duplication. We report here the molecular, cytogenetic, clinical and neuropsychiatric evaluations of a family in whom 3 of 4 siblings inherited an interstitial duplication of 15q11-q13. This duplication was inherited from their mother who also had a maternally derived duplication. Affected family members had apraxia of speech, phonological awareness deficits, developmental language disorder, dyslexia, as well as limb apraxia but did not have any dysmorphic clinical features. The observations in this family suggest that the phenotypic manifestations of proximal 15q duplications may also involve language-based learning disabilities.

A complex of insects which can cause moderate to severe crop damage attacks peanuts in the North Carolina-Virginia production area. Wild species representing the seven sections of the genus Aracbis L. were evaluated for resistance to tobacco thrips (Frankliniella fusca Hinds), corn earworm (Hefiotbis zea Bodie), and potato leafhopper (Ernpasca fibae Harris) during a 3-year field study. Very high levels of resistance for these insects were identified in several species collections. Because collections in section Aracbis were among the species with the highest resistance levels, utilization of the germplasm resources to improve cultivated peanuts should be possible. In addition to evaluating species collections, 40-chromosome (A. hypogaea x wild species) hybrid derivatives were evaluated for resistance to the three insect pests plus southern corn rootworm (Diabrotica undecirnpunctata bowardi Barber). Selections with resistance levels equal to or greater than the cultivar NC 6 were made for corn earworm and southern corn rootworm. Laboratory tests of several Aracbis species indicated that a mechanism of resistance to H. zea is antibiosis. Because the levels of resistance to several insects have been greatly increased in lines of A. hypgaea, evidence exists for germplasm introgression from wild to the cultivated species of peanuts. ~

No abstract

Advanced generation 40-chromosome hybrids between A . hypogaea (2n = 4x = 40) and a wild diploid species, A . cardenasii were evaluated for early leafspot, Cercospora arachidicola resistance and agronomic potential . The objective of this investigation was to determine if early leafspot resistance derived from a wild species could be incorporated into the A . hypogaea genome . Interspecific hybrid selections were made and then compared in the field and greenhouse to susceptible cultivars and to A . hypogaea lines which are reported to be resistant to early leafspot . Significantly higher levels of resistance were found in five hybrid selections than in cultivated lines based on numbers of lesions per leaf. In a greenhouse study, several hybrid selections also had greatly reduced sporulation from lesions as compared to A . hypogaea. Several mechanisms of resistance are believed to be present . Although hybrid selections had small seeds and low yields as compared to A . hypogaea, a new and valuable source of early leafspot resistance derived from the species A . cardenasii is present .

Geographic Information System (GIS) tools are applied to a comprehensive database of 3514 records of wild Arachis species to assist in the conservation and utilisation of the species by: (a) determining the distributional range of species and their abundance; (b) characterising species environments; (c) determining the geographical distribution of species richness; and (d) determining the extent to which species are associated with river basins. Distributional ranges, climatic variables and indices of endemism for each species are tabulated. A. duranensis Krapov. & W.C. Gregory, the most probable donor of the A genome to the cultivated peanut, is distributed in close proximity to both the proposed donor of the B genome, A. ipae¨nsis, and the closest wild relative of the cultigen, A. monticola Krapov. & Rigoni. This region in the eastern foothills of the Andes and the adjoining chaco regions of Argentina, Bolivia and Paraguay, is a key area for further exploration for wild Arachis. An area of particularly high species richness occurs in the State of Mato Grosso, close to the Gran Pantanal in southwest Brazil. Seventy-one percent of the species were found to have some degree of association with water catchment areas, although in most cases it was difficult to determine whether this was due to climatic adaptation reasons, restricted dispersal due to geocarpic habit, or the role of watercourses as a principal dispersal agent. In only two cases could climatic adaptation be eliminated as the reason for species distribution.

No abstract